


Sticky Sexcapades

by GetMcDunkedOn



Series: Pheromones n Bones [2]
Category: Undertale (Video Game)
Genre: Anal Fingering, Foreplay, Interrupted Sex, M/M, Mistaking something for lube, Mpreg, Sans/Underfell Sans (Undertale), Sex Toys, Sexual Humor, Sibling Embarrassment, Skeleton Pregnancy (Undertale), That's not lube, Underfell Papyrus (Undertale), Underfell Papyrus/Underswap Papyrus (Undertale), Underfell Sans (Undertale), Underswap Papyrus (Undertale), superglue
Language: English
Status: Completed
Published: 2021-02-07
Updated: 2021-02-07
Packaged: 2021-03-12 06:03:02
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,794
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29255655
Author URL: https://archiveofourown.org/users/GetMcDunkedOn/pseuds/GetMcDunkedOn
Summary: Red and Sans try to have a grand ol' time with some lube and a toy. But that's not lube... Oh no.
Relationships: Sans/Sans (Undertale)
Series: Pheromones n Bones [2]
Series URL: https://archiveofourown.org/series/2148276
Comments: 16
Kudos: 35





	Sticky Sexcapades

**Author's Note:**

  * For [Diyami](https://archiveofourown.org/users/Diyami/gifts).



> Written for Diyami! It's in the Omega's Respite universe, set some undefined time not long before the events of the start of the fic.

It was the weekend, and that meant Red didn’t have school to go to, and Sans didn’t have school to teach. Of course, Red had work that evening, but now it was morning, and morning was for fuck. With Catpernicus safely deposited outside the bedroom so there was no awkward cat shenanigans during sex, Red was all over his datemate, straddling him and kissing hungrily. His magic was pooled in his pelvis, not yet formed, and he teased at Sans’s member with a magic hand. Sans moaned underneath him, arching up a little, petting Red’s spine. The way his fingers dug into the spaces between each vertebra had Red shivering, his magic dropping into place.

“fuck, baby,” Red mumbled, spreading his legs a little more. “you’re gonna make me not wanna bother with these toys.”

“heh, well we can’t have that.” Sans grinned against Red’s mouth, pulling back to wink. “you promised me i’d get to wreck you with this vibe, and i really wanna see that~”

“now, now, i never said ‘i promise.’ but you’re right.” He chuckled a little as he reached over to grab the thick, silicon vibrator he’d just recently bought. He held it up and wiggled it before Sans snatched it, then also reached over to blindly grab for the bottle of lube he knew he’d put somewhere around here. His hands found a bottle, and he pulled it over to flip open and pour something clear onto his fingers. Then he dropped said bottle and wasted no time in reaching back to start to stretch himself out.

Sans busied himself being sexy as he watched Red work, sockets half-lidded as he licked the silicon toy. He was slicking it up with his sweet vanilla tongue, humming into it like he was pretending it was Red’s dick. Red was very distracted by it, so much so that he didn’t immediately notice something was wrong. But soon enough, as he moved his fingers, he became aware that it was getting difficult. Very difficult. He managed to snap out of his lust-fueled haze enough to look away from Sans’s sinful tongue, glancing back.

“huh…?” he mumbled, pulling his fingers away. Except they didn’t come, still very much lodged inside his back entrance. Stuck. His fingers were stuck. He tugged again, and still, they didn’t move.

“babe, what’s wrong?” Sans asked, stopping his sexy tonguing of the vibe. He looked down to Red’s hand, brow furrowing a little. “did you nick yourself or something?”

“no, i…” He yanked again, harder, and nearly tugged himself right off of his datemate from the force. More confused than ever, he looked back at Sans. “i’m stuck??”

“what do you mean, you’re _stuck_?”

“i, i mean i’m stuck! my fingers, they won’t move, they won’t come out.”

“what the heck did you do, red?”

“i dunno, i was just stretching myself out with the lube!”

Sans frowned, glancing over at the still-open tube on the bed beside them. He picked it up, noting it was sticky now, and read the label.

“prototype stick-fast superglue alternate… what is this?”

“h-huh?” Red felt his soul drop. “no way, what, lemme see that.” He reached outwith a magic hand to grab Sans’s wrist and tug the bottle closer.. He read and re-read the label, his eyelights going out. “th-this is…”

“glue…?”

“oh, fuck. this. this is my prototype. i’m testing out glue that dries faster than superglue. like, within seconds instead of minutes.”

Sans frowned up at him, then behind him. “so you… you glued your fingers into your ass?”

“well… yeah… i guess…”

Sans snorted. Then he started to laugh, his free hand coming up to smack at his forehead as he giggled. Red turned his namesake, sweat building up on his forehead.

“it’s not funny, sans!”

“you glued your fingers into your ass!”

“it’s not funny!! i dunno how to unglue this yet, it’s a fucking prototype!”

Sans still giggled a little, trying to put the bottle down and lift his hand.. The bottle came with. The mirth in his expression faded as he tried to pull his fingers off the tube, but they wouldn’t come. It was stuck.

“oh…” Sans said. “oh, shit.”

“yeah, not so fucking funny now, huh??”

“alright, red, calm down, baby.” Sans reached up with his free hand to stroke Red’s cheek a little. “it’s ok. we’ll figure this out. it’s gonna be ok. i’m sure some warm, soapy water would loosen it up like regular superglue.”

“what if it doesn’t?” Red asked, leaning into the touch a little despite his ire with his datemate. “it doesn’t use the exact same chemical makeup as superglue, i made modifications to decrease the bonding time…”

“we’ll try it, and if it doesn’t work, we’ll try other things. we’re both scientists, it’ll be fine.”

“alright… alright, okay. let’s fill up a bucket or something.”

“yeah, i’m on it, baby.”

Sans started to try and get up - then flailed and collapsed a little. He sat up again, confused, and looked down. A thin trickle of the glue had spilled out from the still-open tube, and now rested between one knee and the sheets. He was stuck to the bed.

“oh, shit,” he said again, a little more urgently. “red? red, babe, i’m stuck to the bed.”

Red stared down at where Sans’s knee was pressed into the sheets, his anxiety building. “shit. ok. uh. i’ll do it. it’ll be fine, i’ll just…” He awkwardly started to get up himself, but with the angle of his hand in his ass, he couldn’t straighten up properly. He, too, toppled a little, landing back on the bed. “shit! shit, shit, i can’t get up, oh fuck.”

“oh man.” Even Sans was starting to look worried. “ok. uh. ok. we. maybe we can get the sheet off the bed, and i can still stand up? use a few extra hands.”

“i can’t, it looks like it soaked through to the mattress, it’s probably stuck too…”

“damn it. ok.” Sans looked around the room. His gaze fell on his jacket, on the floor. He flushed blue. “red… we gotta call someone for help.”

“what??” Red popped his head up again, and followed Sans’s gaze. He could get a magic hand there, that wasn’t as difficult. It was a really good idea. But… His soul cramped. “oh, nu-uh. nope. nobody else is gonna hear about this. no way.”

“baby, we don’t have a choice. unless you wanna be stuck this way ‘til we starve, we need help.”

“but we’re both naked!”

“i’m sure we’re not the first two idiots to get stuck during sexy times, red, ok, we’ll live.”

Red whined, his face still flushed. But after a long moment, he sighed and put his head back down. A magic hand manifested and pulled out Sans’s phone, bringing it over. Sans took it and opened his contacts.

“call pa-”

“ _hell_ no,” Sans said before Red could even finish. “my baby bro is _not_ seeing this.”

“but we gotta!”

“anyone else. literally anyone.”

Red groaned. He knew the next best option, but he didn’t like it. “okay, okay… fine…”

\- - - - -

“REMIND ME AGAIN HOW EXACTLY YOU _BOTH_ MANAGED TO GET STUCK SO THOROUGHLY?” Vex asked, tapping the fingers of one hand on the opposite arm. His brow was raised as he gave them both a critical look. Sans had desummoned, and a blanket was over Red’s dick, at least, but Red had had to show off the fingers stuck in his ass. He burned with shame, hunched, looking down.

“it just kinda happened, boss, ok, i’m sorry…”

“WELL, YOU DON’T HAVE TO APOLOGIZE. _I’M_ NOT HURT.” Vex was trying very hard to keep a straight face and only look stern, despite wanting to laugh in his big brother’s face. Of all of the antics Red had gotten into over the years, this was by far the most ridiculous. “BUT I AM GOING TO HAVE TO BE THE ONE TO WASH IT OFF, SO, PERHAPS IT’S STILL APPROPRIATE.”

“ok, boss, please,” Red whined. “we’re dumb, i know, just c’mon, this already sucks enough.”

Vex took pity, going to fill a bucket with warm soapy water.

Luckily, despite the tampering with the chemical compounds, it seemed to do the trick well enough. Both stuck skeletons got a partial bath, and the bed was nice and soaked with soapy water, but they could at last both get up, all trace of sticky mess gone. The messy, glue-covered tube was closed and thoroughly soaked as well, and Red angrily put it in a bag and locked it in a drawer, not to see the light of day ever again, or at least not until he could get over the embarrassment of having his twin brother soak his ass.

“thanks, bro,” he mumbled, pulling his clothes back on. He was thoroughly no longer in the mood for sex. Sans also got dressed, then wrapped his arms around his datemate and nuzzled him.

“yeah, thank you, vex. that was really a _sticky_ situation.”

Vex sighed loudly at the pun. “YOU’RE WELCOME. YOU’RE BOTH LUCKY I DIDN’T TAKE PICTURES FOR BLACKMAIL. YOU OWE ME ONE.”

“yeah, yeah, just don’t tell anyone.”

“I WON’T MAKE ANY PROMISES. STRETCH WILL FIND THIS HILARIOUS, I’M SURE.”

“boss!” Red whined. Again, Vex relented and stopped his teasing.

“ALRIGHT, ALRIGHT. I WON’T TELL ANYONE, NOT EVEN MY HUSBAND. PROMISE.”

“thank you. geez.”

“BUT YOU REALLY DO OWE ME ONE.”

“uh-huh, uh-huh, bye now.”

He tried to push Vex to the door. Finally letting the amusement show on his face, Vex let himself be pushed. One last wave, before he left their house again to return home. Red sighed again, almost a whine, and Sans gave him another nuzzle.

“it was a little funny, red.”

“it was not,” he lied.

“uh-huh, c’mon, let’s go cuddle on the couch with some popcorn and some how the universe works.”

That made Red perk up, and he obeyed, settling down on the couch with his favorite show.

\- - - - -

When Vex got home, he snuggled up to his pregnant mate, Stretch sleepily blinking up at him.

“what’d they need, love?” Stretch asked, and Vex gently smoothed a thumb over his lover’s cheek.

“THEY GOT INTO SOME SHENANIGANS AND NEEDED ASSISTANCE. UNFORTUNATELY, I AM SWORN TO SECRECY.”

“secrecy? what?”

“JUST TYPICAL RED ANTICS. HE’S A HANDFUL. SOMETIMES I HAVE NO IDEA HOW HE THINKS OF HIMSELF AS THE OLDER ONE. WE’RE TWINS, ANYWAY.”

“heh. i know the feeling. c’mon, tell me, though~ tell me, tell me.”

“A PROMISE IS A PROMISE, EVEN IF IT’S ABOUT SOMETHING SO RIDICULOUS.”

“aww. fiiiiiine. just snuggle me. the baby’s really tiring today.”

“THAT, I CAN DO.” He pet Stretch again, then settled in for a lazy Saturday.

**Author's Note:**

> Poor boys ;)


End file.
